1. Field of the Invention
The present invention relates generally to apparatus and methods for detecting parameters of living organisms and, more particularly, relates to a device and method for providing an output signal indicative of a parameter or parameters of a living organism, which output signal being derived by detecting the potential of the electromagnetic field present between a reference point and a test point or test points of a living organism.
2. Prior Art
Over the years there have been two prevailing theories on the operation of living organisms. The more widely accepted theory even to this day is that all living organisms are made up of discontinuous entities called cells, which are organized in accordance with the interaction between themselves. This is often referred to as the cell theory of life or physiology. Its modern origin is based on the work, among others, of Harvey and Laviosier, who respectively applied this atomistic theory to explain the circulation of blood and the chemical nature of respiration and metabolism. Their analysis of life was based upon the mechanistic premise that life was no more than a complex reaction between discontinuous chemical or atomic entities. In summary, this analysis states that a living organism is equal to the sum of its parts. Even today, molecular biology and medicine rests on this analysis.
The less widely accepted theory is often referred to as vitalism. Vitalism states that a living organism is greater than the sum of its atomic constituents. Vitalism in essence postulates that there is a non-atomic force that acts to organize the atomic constituents. This non-atomic force was used to explain the constancy of form of organisms over time despite ongoing chemical reactions, which constancy could not be explained by the cell theory. Vitalism has gone under several names: Driesch's "entelechy," Rignano's "biological energy," Child's "physiological gradient," and Kohler's "Gestalten." Vitalism, however, fell into disrepute because the non-atomic force could not be empirically demonstrated.
In the 1920's and 1930's, Harold S. Burr of the Yale School of Medicine and Filmer S. C. Northrop of the Yale School of Law set forth their theory addressing the problems of both mechanism and vitalism. Their electrodynamic theory states that "the pattern or organization of any biological system is established by a complex electrodynamic field, which is in part determined by its atomic physio-chemical components and which in part determines the behavior and orientation of those components." Burr, H. S. and F. S. C. Northrop, "The Electro-Dynamic Theory of Life," Quarterly Revue of Biology, Vol. 10, pages 322-333, 1935. The theory synthesized the cell and vitalism theories by applying modern relativistic field physics to biological systems. In essence, this electromagnetic field (also referred to as a quasi-electrostatic field) is the intermediary vector force between Cartesian and Gaussian coordinates.
This electro-dynamic field postulated by the theory was empirically demonstrated. Burr, H. S. and C. I. Hovland, "Bio-Electric Potential Gradients in the Chick," Yale J. Biology and Medicine, Vol. 9, pages 247-158, 1937. Burr, H. S. and C. I. Hovland, "Bio-Electric Correlates of Development in Amblystoma," Yale J. Biology and Medicine, Vol. 9, pages 540-549, 1937. The potential level of the electro-dynamic field was measured using a very high impedance vacuum tube volt meter (VTVM) and special electrodes. Each electrode was designed in accordance with Willard Gibb's equations governing the mechanics of fluid junction potentials so as not to generate an offset potential between itself and the organism being measured. The high impedance, typically 10 megohms, of the VTVM was calculated in accordance with Maxwell's equations and was necessary to prevent any appreciable current from being drawn from the organism and to eliminate any errors caused by changes in the resistance of the organism test interface. The electro-dynamic field would be distorted causing a disturbance to the organism and an error in the potential level value if appreciable current was drawn during the test.
Despite repeated empiric demonstrations of the validity of the electro-dynamic field theory by Dr. Burr and others, major technical problems contribute substantially to its failure to become an established diagnostic and predictive means for indicating the state of a parameter or parameters of a living organism. Reference and test electrodes produce errors due to their design, temperature variations, and the uneven pressure between the organism and the electrodes. The available structures and configurations of these electrodes is also quite limited and cannot be tailored for many test applications.
The potential level of the electromagnetic field of organisms usually does not exceed an absolute value of 100 millivolts. Therefore, a resolution of 100 microvolts is needed to obtain a measure of the field of sufficient accuracy to ascertain a diagnostic parameter or parameters. Conventional high gain instrument operational amplifiers exhibit a characteristic temperature coefficient for output bias voltage of 700 microvolts per degree Centigrade. Thus, the desired resolution of 100 microvolts cannot be achieved unless the ambient temperature of the operational amplifier is kept within one-seventh degree Centigrade during the entire test. This narrow temperature tolerance is not possible, however, unless a very expensive, technically complicated, physically cumbersome, and high electrical load temperature control system, such as a temperature oven, is used in conjunction with the operational amplifier.
Another problem associated with temperature variation is that the very slowly varying electromagnetic field often has a period of substantial time, such as 30 seconds or more. If real time integration is used as the measuring technique, conventional high gain operational amplifiers cannot provide the necessary 100 microvolt resolution for a time period greater than 2 seconds, because the ambient temperature of the amplifier cannot be maintained within the one-seventh degree centigrade range without the use of a temperature control system as stated above.
A further problem is the presence of undesired alternating current signals having frequencies, for example, greater than 100 Hertz and undesired charges present on the electromagnetic field signals furnished to the measuring apparatus and method by the reference and test electrodes. These undesired alternating current signals and charges act to mask the desired slowly varying DC signal indicating the potential of the electromagnetic field. The problem becomes particularly severe in areas having high levels of electromagnetic radiation produced by television, radio, communication radio frequency transmissions, etc., which affect the electromagnetic fields of organisms. In addition, natural environmental events, such as sunspots, also affect the electromagnetic field of organisms.